The ignition key in the start position causes the starter relay to operate and provide power to the starter motor.
You should hear an audible click of the relay - usually on top or very close to the starter - if you hear the click then suspect the starter motor - if you don't hear the click suspect the switch or the relay or the wire that runs to the relay.
It used to be the case that sometimes the toothed dog on the starter would jam up against the flywheel - the fix for that was to engage 2nd gear and rock the car back and fore to move the flywheel a few degrees. I suspect that this may not be an issue with modern engines.
I know absolutely nothing about motor vehicles.
Good luck...
Clarkson
November 2014